Sunglasses provide comfort for human wearers by attenuating bright light. Most modern sunglasses also filter out ultraviolet (UV) light (which can harm the eye with long-term exposure) and many also filter out infrared light (which can cause ocular discomfort and aggravate certain eye conditions). Some sunglasses operate on the principle of aggressively blocking certain portions of the visible spectrum: an example of these are blue-blocking amber sunglasses. Such sunglasses typically feature high transmission of yellow, orange, and red, diminished transmission of green and blue-green, and virtually no transmission of blue and violet. Color values, as perceived by the typical human eye, are highly distorted by lenses of this type, and—despite acceptance of amber tinting to enhance contrast—loss of chromatic contrast results because their deep yellow-orange tint weakens color differentiation. Certain other color filtering lenses have been made available in the marketplace including those disclosed in U.S. Pat. No. 6,145,984, which is incorporated by reference herein.
A portion of light reflected from many surfaces such as a flat road or water generally is horizontally polarized. This means that, instead of light being scattered in all directions in more usual ways, at least some of the reflected light generally travels in a more horizontally oriented direction relative to the reflecting surface(s). This creates an annoying and sometimes dangerous intensity of light that the human eye experiences as glare. Polarized eyeglasses reduce glare by blocking horizontal light waves which being reflected off various surfaces, as is well known in the optics art. Horizontally-polarized light that is reflected off horizontal surfaces—and to a lesser degree, diagonal surfaces—can be blocked or at least reduced by polarized sunglasses when the polarizing element is oriented in a given way relative to the light and the wearer's eyes. This improves visibility of those surfaces, and—in the case of water and other transparent media—polarized lenses may provide for increased visibility beneath the water or other media surface. By removing or at least reducing blinding reflected glare, and a wearer's need to squint when facing it, polarized lenses also provide increased eye safety and comfort for the wearer. Current lens providing polarization and a desirable color transmission profile typically are at least 3 mm thick.
It may be desirable to make available a thinner and therefore lighter eyewear lens that also provides desirable color transmission characteristics for a human eye, and that may also include an effective polarizing element.